_Critique_ is intended to issue in a new and genuine body of metaphysical teaching. The key to the whole problem of the four questions is not to be found in the _Critique_. This section is transcribed from §§ 4-5 of the _Prolegomena_, and is consequently influenced by the general arrangement of the latter work. This fourfold division was indeed devised for the purposes of the argument of the _Prolegomena_, which is developed on the analytic method, and for that reason it cannot be reconciled with the very different structure of the _Critique_. Yet even the _Prolegomena_ suffers from confusion, due[303] to Kant’s failure to distinguish between universal and relative natural science on the one hand, and between immanent and transcendent metaphysics on the other. The four questions do not coincide with those of the _Critique_. Instead of the third--how is metaphysics as natural disposition possible?--we find: _how is metaphysics in general possible?_ In §§ 4, 5, Kant’s argument is clear and straightforward. Pure mathematical science and mathematical physics are actually existing sciences. The synthetic _a priori_ judgments which they contain must be recognised as valid. Metaphysics makes similar claims. But, as is sufficiently proved by the absence of agreement among philosophers, its professions are without ground. It transgresses the limits of possible experience, and contains only pretended knowledge. This false transcendent metaphysics is refuted in the _Dialectic_. Kant was, however, equally convinced that an _immanent_ metaphysics is possible, and that its grounds and justification had been successfully given in the _Analytic_. His problem as formulated in the _Prolegomena_ is accordingly threefold: (1) how are the existing rational sciences, mathematical and physical, possible? (2) _in the light of the insight acquired by this investigation_, what is the origin and explanation of the existing pretended sciences of transcendent metaphysics? and (3) in what manner can we establish a positive metaphysics that will harmonise with reason’s true vocation? So far all is clear and definite. But the unresolved difficulty, as to the relation in which natural science and immanent metaphysics stand to one another, brings confusion in its train. As already noted,[304] in § 15 natural science is displaced by immanent metaphysics (though not under that name); and as a result the fourth question reduces to the second, and the above threefold problem has to be completely restated. The _Prolegomena_ has, however, already been divided into four parts; and in the last division Kant still continues to treat the fourth question as distinct from that which has been dealt with in the second division, though, as his answer shows, they are essentially the same. The answer given is that metaphysics as a science is possible only in and through the _Critique_, and that though the whole _Critique_ is required for